


fighting spear-it

by spasticbirdie



Category: Undertale (Video Game)
Genre: Alphyne, Alphys/Undyne-centric, Anal Sex, F/F, Magic Lava Lamp Dong, Rough Oral Sex, Rough Sex, Strap-Ons, Trans Alphys, Trans Female Character, basically? can't really think of a better tag to use uhhh, get ready for some dang filth, hoo boy, i'm really just bad at tagging things in general so enjoy this smut, the whole thing we did with sans and yeah i'm giving undyne the magic dong treatment, yeah I'm going there
Language: English
Status: Completed
Published: 2017-05-10
Updated: 2017-05-10
Packaged: 2018-10-30 04:34:46
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 5,386
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10869225
Author URL: https://archiveofourown.org/users/spasticbirdie/pseuds/spasticbirdie
Summary: Undyne tries teaching Alphys how to use magic, and Alphys comes up with some new ways to use it.





	fighting spear-it

**Author's Note:**

> title idea credit to mado @alphyies  
> i don't really have anything to say here. i wrote more smut. take it already.

Legs crossed on the yoga mat, fingers steepled in front of her, and eyes shut tight, Alphys tried very hard to follow Undyne’s instructions.  _ Focus. Breathe naturally, don’t think about it. Just imagine it welling up inside you, flowing forth, and then slowly focusing into… _

_ Into… _

Alphys cracked one eye open.  _ How did Undyne say to do it again? _

Alphys and Undyne were at the gym Undyne frequented and often trained people at, each sitting on a yoga mat facing each other in a quiet, secluded training room. Undyne was in the same pose as Alphys; legs crossed, eyes shut, hands forming an arch in front of her. She was wearing a snug-fitting sports bra that showed off the definition of her abs and gym shorts, her hair tied up in a tight ponytail. Undyne had picked out some exercise clothes for Alphys too; a snug-fitting pair of yoga pants and a torso-hugging tank top. Alphys felt incredibly self-conscious in both. 

As Alphys watched her through one eye, hoping to pick up some hint as to what she was doing wrong, a faint glow started forming around Undyne; a light blue aura that looked like condensed smoke. Slowly, the aura focused closer and closer to Undyne’s skin, and finally seemed to absorb into her body. Undyne took a deep breath and opened her eye, and Alphys quickly shut hers again, trying to look like she was doing the same thing as Undyne was.

“Just like that.” Undyne looked to Alphys encouragingly. “Focus, breathe, let it flow, and then pull it back. How’re you doing?”

Alphys, her eyes still screwed shut, tried to do as Undyne said. She focused as hard as she could, but tried to relax, but also tried to...pull it back?

She had no idea if she was doing it right, but suddenly, Alphys started to feel something. Like something was beginning to swell up within her.  _ Okay, _ she thought.  _ Now just let it out, like Undyne said, and- _

“Urrrrrrp.”

Alphys’ burp bubbled out, bouncing around the empty room for a few seconds before dying awkwardly in silence. Alphys’ eyes popped open in embarrassment, she started a little, and then fell over backwards.

Undyne stared for a few seconds before she broke out laughing. “GAHAHAHAHAHAHA!” 

Alphys started going red with embarrassment as she got back to her feet. Undyne nearly fell over herself as she shook with laughter. “Ohhhhh my god, Al. Nice one.”

Alphys was red as Undyne’s hair as she got back on her knees. “W-well, that went great,” she muttered, still burning with embarrassment.

“Aw, don’t take it too hard, babe.” Undyne uncrossed her legs and stood up. “I mean, it took me YEARS to get magic right. And even when I got the hang of controlling it I could only manifest like, a stick.” As if to demonstrate, a spear suddenly appeared in her hand, and Undyne twirled it around.

“I s-still don’t really get why I’d even n-need to learn this stuff.” Alphys stretched as she stood up. “It’s not like I ever r-really get in f-fights or anything.”

“Well, there’s a lot else you could use it for! Uh, hang on, watch this.” The spear disappeared from Undyne’s hand, and she sat back down, cross-legged, focusing.

As Alphys watched, the blue aura around her reappeared, hovering just barely off her skin. Slowly, it seemed to slide up her torso and down her left arm, collecting in a noticeably heavier field around it. Undyne let out a breath, raised her arm, and flexed.

Alphys blushed a little redder.

As the muscles in Undyne’s arm tightened, the aura of magic surrounding her arm seemed to peel away, and formed a second arm that split from her real arm at the shoulder. The second arm also flexed. Alphys watched in awe.

Undyne relaxed her muscles and grinned. “Pretty cool, huh?” She crossed her arms (her real ones) as the magic arm ran its fingers through her hair, flicking her bangs away.

“That is...so....AWESOME!” Alphys jumped up, her own failure to muster any magic forgotten. She ran over to Undyne, circling around her and inspecting the magical appendage. “I had no idea you could do stuff like that!” She rested a hand on Undyne’s arm; it felt slightly cool to the touch, and there was a bit of give to it, like her hand would just push right through if she forced it.

“Gerson showed me how to do it.” Undyne scratched her chin, arms still crossed. “Well, more like he did it a lot back when I was a kid and I begged him to show me how but he said it was way beyond me. So I kinda ended up figuring it out for myself, I guess.” She grinned. “Oh man, he’s gonna be floored when I show him.”

Alphys kept inspecting Undyne’s arm. It was a carbon copy of her real arm; skin scaly and tight over her bicep and scarred here and there. It even had the same texture, albeit with the strange sort of softness Alphys had felt before. Alphys poked and prodded, Undyne watching her with amusement.

Moving up to Undyne’s hand, Alphys interlaced her fingers with Undyne’s glowing blue ones. Again, it felt almost exactly like Undyne’s real hand, all rough skin and scars. Alphys stared, still fascinated, still inspecting.

“Al…”

Alphys took Undyne’s pinky finger and bent it backwards. A little too hard.

“Ow!” Undyne flinched back, and suddenly her arm dissipated into a cloud of heavy mist which hung in the air for a moment before disappearing.

“S-sorry! I didn’t realize that you, uh, could feel through it…”

“It’s okay, it’s okay.” Undyne stretched her real arms, giving her left a rub. “Leaves me with some sorta weird tingly feeling, though. Like, phantom pain or something.” She rolled a shoulder and grinned again. “But hey, if you think that’s cool…”

Undyne closed her eye and focused again. Her aura flared up, then began refocusing, this time pulling in from her arms and legs, into her torso, and down. It moved past Undyne’s stomach and then…

Disappeared? Alphys cocked her head in confusion. She couldn’t see where Undyne’s aura was collecting this time.

Then, Undyne stood up, eye still shut. Not without embarrassment, Alphys saw that her aura was focusing around her lower back and rear.

“Okay…” Undyne opened her eye. “Haven’t tried this out for real yet, so…” She took a deep breath, turned away from Alphys, and tensed her legs and rear up.

Alphys blushed. Again.

The condensed blue smoke began to expand outward and downward from Undyne’s body, forming a long, heavy tail that was thick at the base and began to taper thinner as it went. Just as it was nearing about the thickness of Alphys’ leg, it flared out vertically, forming a large, pointed fin on the top and a smaller one on the bottom.

She wasn’t done yet. Undyne took another deep breath, rolled her shoulders, and then tensed them up. 

Alphys decided she really had to stop going red every time she saw her girlfriend’s muscles.

From the small of Undyne’s back, more of the blue, thick smoke began to bubble forth. It poured over her upper back before concentrating in a long, curved fin that ran from the base of her neck to the middle of her back and hooked just a little downward at the bottom. As the fin finished forming, a tiny flame sparked at the tip for just an instant before fizzling away.

Finished, Undyne relaxed her muscles, cracked her neck, and flashed Alphys a sharklike grin. “Whaddya think?” She swung her tail back and forth a few times, then turned back to Alphys, tail sweeping slowly back and forth behind her.

Alphys was as red as Undyne’s tail was blue. Wordlessly, she circled around Undyne, watching as her shark tail swished gently, naturally across the floor. She rested a hand on it, eliciting a small reaction from Undyne, and ran her hand from the end up to the base, where it flowed forth seamlessly from Undyne’s back. Alphys continued up Undyne’s back and ran her hand over the fin, which protruded just as naturally from her back as any other body part.

After resting her hand there for a moment, almost swearing she could feel Undyne’s pulse through the fin, Alphys took her hand away, marched determinedly back to her mat, sat crosslegged again, steepled her fingers, and shut her eyes. “How did you say to do it, again?”

 

“Hey...Unnie?”

“Yeah, babe?”

There were back in their apartment, sitting on the couch, both holding controllers and playing a fighting game. Undyne had her arms wrapped around her girlfriend, her controller resting just in Alphys’ lap, her head resting on Alphys’ shoulder.

On screen, Alphys’ character threw a fireball that Undyne’s just barely dodged.

“So, I kinda wanted to know a bit more about, uh, how you did, that, thing. With the magic, and your arm, and the tail, and stuff.”

“Well, I dunno if I could really tell you. I think it’s kinda become second nature to me at this point, it’s kinda hard to explain exactly how…”

Undyne’s fighter tried to grab Alphys’, but she countered, suplexing Undyne’s to the ground.

“Okay, well...maybe not how you do it, I guess, but what you  _ can _ do with it? I dunno.”

“No, I get you. Hmmmm… well, you saw my arm and tail and all that.”

“So you can do more than just, l-like, copy your body parts?”

“Yeah, I suppose. Copying is a lot easier than making something out of nothing, though. I wasn’t even sure I could get that tail right, haha.”

Alphys’ character hit Undyne’s with an uppercut, sending her flying.

“B-but that’s, like, really big and, uh, not like a normal body part.”

“I guess, yeah. It’d probably be easier to make, like, a third eye or something.”

“S-so, uh…”

“Al?”

Alphys paused the game and put down her controller, twiddling her thumbs in her lap. “I was just, uh, kinda wondering if you could make, uh, a normal body part you don’t have,” she finished.

“Al.”

“Like, if it’s something that, uh, you could theoretically have, but don’t, but isn’t, uh, something outlandish like a tail or something, uh, like…”

“Al…”

“L-like, I dunno, uh…”

“Alphys.” Undyne dropped her controller and removed her arms from Alphys’ waist, crossing her arms and looking like she was trying not to laugh.

“Like...uh…”

Alphys gave up and clambered out of Undyne’s lap, turning to face her. “Undyne, I am FURIOUSLY bisexual.”

“Ohhhhhh my god.” Undyne put her face in her hands, stifling laughter.

Alphys forged ahead. “I mean, y-you don’t HAVE to and if you can’t it’s totally ok, but, I thought, uh, you m-might be interested in trying,” she finished awkwardly.

Undyne sat silently, fingers steepled in front of her face. She took a deep breath, then stood. “Wait here a minute.” Hopping off the couch, she walked briskly to the bedroom and shut the door behind her.

“O-okay.” Alphys sat nervously on the couch.

 

_ Oh my god oh my god oh my god. _

As the bedroom door swung shut behind her, Undyne leaned on it and internally whirled.  _ Oh my god. Oh my god is Alphys into that kinda stuff.  _ Mentally, Undyne hit herself.  _ Yes, you already knew that you idiot now what are you gonna do about it.  _

After calming down, Undyne walked over and sat on the edge of the bed, nervously bouncing a little.  _ Okay, let’s do this. _

She stripped off her shirt, pants, and pulled her hair tie out, letting her ponytail fall into a stream of red hair down her back. Sitting crosslegged on the bed, she closed her eye, steepled her fingers, and…

_ No, no no no. Not enough.  _ Quickly reaching around her back, she undid her bra and tossed it to the side, then slipped her panties off and discarded them as well.

_ Ok. _

_ Now what does having a dick feel like? _

....

_ Oh, so that’s what it feels like. _

 

Back in the living room, Alphys sat nervously on the couch, fretting up an absolute storm.  _ Oh my god what did I just DO that was such a weird thing to ask her she’s gonna hate me and think i’m weird and oh god it’s such an unreasonable request to make I don’t even know how hard doing that is for her stupid stupid stupid _

“Alphys?”

Undyne calling from the bedroom snapped Alphys out of her spiral. “Y-yeah?”

“Come on innnnn~” Undyne called in a sing-song voice.

Nearly tripping five times in the short walk to the bedroom door, Alphys stopped on the threshold and took a deep breath.

She pushed the door open a crack and poked her head in.

“Hey, Al.”

Undyne was lying on the bed, on her side, facing away from Alphys. One hand was propping up her head, and the other was resting on her hip. Her hair was down, falling over her back and onto the bed.

She was also very much naked. Alphys’ eyes wandered from Undyne’s flowing red hair, down her well-defined shoulders, over the crisscross of scars on her back, to her tight, toned rear and legs.

As Alphys stepped into the bedroom, a little hesitantly, Undyne rolled over to her other side, now exposing her front. Alphys’ eyes wandered the same way again; from the bedroom eyes she was flashing Alphys, across her sharp shoulders and round, well-shaped breasts that still didn’t hide the muscle beneath, down her torso that was just as scarred as her back, past her still-soft dick, over her toned legs agai-

Alphys did a double-take. Flowing seamlessly from Undyne’s groin, in the light blue color of her magic, was a half-erect penis, looking about five inches long in its not-quite-hard state. A pair of round, shapely balls hung beneath it, already beginning to pull in tighter as Undyne’s dick slowly hardened.

There was a momentary silence as Alphys took it all in.

“So… whaddya think?” Undyne asked, sitting up cross-legged, her dick resting on her legs.

Inwardly, her heart was absolutely pounding.

Alphys didn’t immediately respond. She shut the door, took one hesitant step towards the bed, then stopped hesitating and stripped down faster than Undyne had ever seen her strip. Moments later, she was sitting across from Undyne, naked, staring down at Undyne’s dick.

“So…Uh…” Alphys hesitantly reached out, internally struggling between arousal of her scientific interest and just plain arousal. She took Undyne’s dick gently in her hands, caressing it tentatively with her fingers.

Undyne let out a little huff. She knew Alphys was just indulging her curiosity, and there was no way she meant to do this, but… god, it felt so teasing, so tantalizing.

Alphys ran a finger up the underside of Undyne’s dick, then gently felt the head and tip, running a finger over her slit. Reaching down with her other hand, she felt the weight of Undyne’s balls in her hand, cupping them and giving them a gentle squeeze.

At this point, Undyne was breathing heavily. “Al…” Her dick was now fully erect and easily over six inches long, a droplet of precum leaking from her slit.

“Wow…” Alphys barely heard her. Running a finger across the tip of Undyne’s dick again, she wiped the precum from her slit and rubbed it between her fingers, then licked them, tasting Undyne’s pre; it tasted a little salty and vaguely bitter. Her dick felt cool and vaguely damp, like Undyne had just been swimming.

“Ngh....” Undyne shivered a little as Alphys continued to touch her, still incredibly entranced by Undyne’s dick. “Alphys… please…”

Alphys looked up from her inspection, then looked back down at Undyne’s dick, only just now realizing that Undyne was on the verge of blowing. “Oh. U-Uh…” Alphys swallowed and wrapped a hand decisively around Undyne’s dick. “I-I haven’t, uh, really done this before, so, uh, If I screw up or anything, um…”

She gave up trying to speak and leaned forward, opening her mouth and then slowly closing her lips around Undynes dick, gently tonguing the head.

Undyne gasped at the wet, warm feeling of Alphys’ mouth around her dick. She was a little clumsy, but her long tongue wrapping all around Undyne’s dick felt heavenly. The whole sensation felt entirely unlike when Alphys ate her out; she could feel Alphys’ tongue gently slide all over her dick, teasing the head and shaft at the same time.

Slowly, Alphys started moving, head moving up and down. Undyne’s dick felt strangely cool and smooth in Alphys’ mouth as it slid over her lips and tongue.

“Alphys…” Undyne breathed heavily, putting one hand on the back of Alphys’ head and squeezing her own chest with the other, moaning. 

Alphys pushed her head forward a little more, and started feeling the head of Undyne’s dick bumping against her throat, forcing little gags out of her. The feeling of her girlfriend’s dick coming so near to fucking her throat made her shiver, and as she continued to suck Undyne off and stroke her dick with one hand, her other slid down her body and began stroking her own dick.

Finally, Alphys pulled off of Undyne’s dick, breathing heavily and swallowing. Undyne came slowly out of her own daze of pleasure and looked worriedly at her. “If you want to stop, we can-”

Alphys took a deep breath, swallowed again, and mouth open wide, pushed Undyne’s dick into her mouth and then with a bit of resistance, taking it all the way down into her throat. Her face pushed into Undyne’s stomach, Alphys gagged, her eyes rolling back in her head.

Undyne gasped. She instinctively grabbed the back of Alphys’ head and held her there as her dick stiffened and then poured a salty load down Alphys’ throat. Alphys felt Undyne’s cum pour out of her dick and coat her throat, sending a bitter scent into Alphys’ nostrils. It was a huge load; Alphys could feel it splashing down into her stomach, and in the midst of Undyne’s ecstacy felt her own dick harden, surge and cum, making a mess of the bed.

Finally, Undyne finished and released Alphys’ head, panting. Alphys extracted Undyne’s dick, hacking and wheezing.

Undyne seemed to come to her senses. “Uh…” She stared as Alphys got her breath back, a bit scared of what she’d done. “Al, I’m…” Losing her concentration, Undyne’s magical appendage disappeared in a cloud of smoke. “A-Are you okay?”

Alphys finally got her breath back. She swallowed, feeling the last few drops of Undyne’s cum slide down her throat. “I’m-” She coughed again, and continued. “I-I’m okay.”

Better than okay, she thought, feeling the dazed afterglow of her own orgasm. She saw Undyne’s dick had disappeared. “Uh...If you want to keep, uh, going…”

She then noticed Undyne’s distressed expression. “Um, um, you didn’t… I’m not, uh… You can…”

Alphys gave up and jumped forward, pulling Undyne into a hug. “I-I’m fine, Unnie.” Undyne tentatively returned the hug, and Alphys leaned up and gave her a quick kiss. “It was fine, I’m alright.”

Undyne kissed her back. “You sure? I didn’t mean to be, uh, too rough with you or anything.”

“It’s okay.” Alphys nuzzled into Undyne’s chest. “I, uh…” The chubby girl blushed a little. “I kinda liked it, uh, rough, like that.”

Undyne’s expression switched from concern to a sharp, predatory smile. “Well. Well well well.” She ran her hands over Alphys’ body; down her back and past her tail, giving her buttcheeks a little squeeze before pulling them apart, exposing Alphys asshole. “You up for some more, then?”

Alphys blushed even more furiously. “I-I…Nnn...”

Undyne ran a finger between Alphys cheecks, applying a little pressure to the ring of muscle. “Well?” she asked seductively.

Alphys was silent for a moment, then pushed away from Undyne and turned around. Down on all fours, she raised her rear, lifted her tail, and spread her cheeks apart. “O-okay.”

Undyne grinned. “Hang on just a sec.”

It was easier the second time. Undyne ran through the whole thing again; focus, let flow, draw back. Her dick manifested quickly, still starting out flaccid.

That didn’t last long, however. Undyne approached her girlfriend’s raised rear and rested her half-hard dick against Alphys’ butt.

_ God, she’s got a great butt _ . Undyne took a moment to appreciate it while she got herself ready; the chubby girl’s rear was big and soft, plenty of fat to squeeze and cuddle. Undyne honestly thought it was a shame that Alphys wore almost nothing but loose-fitting dresses and saggy sweatpants that failed to really show off her rear (which was partly why she had insisted on Alphys learning magic; it was worth it to see her in form-fitting yoga pants). She squeezed Alphys’ butt, feeling the soft-yet-also-scaly texture of her skin, rubbing her dick gently between her cheeks and feeling it bump against the base of her tail…

_ Actually, that feels really good _ . Undyne squeezed Alphys’ cheeks together around her dick, feeling her soft ass sandwich around her. Grinding her dick a little harder against Alphys’ ass, she grunted, her shaft rubbing against the tight ring of muscle of Alphys’ asshole.

Undyne sped up, her dick sliding back and forth against Alphys’ butt. Her stomach bumped against Alphys’ rear. The wetness of her dick provided some nice lubrication, and soon Undyne’s dick was making wet  _ shlik _ ing noises as she fucked Alphys’ butt.

“Ngh…” Her torso was slapping against Alphys rear as her movements intensified, sending Alphys’ ass jiggling with the impact. She squeezed Alphys’ rear as she felt her orgasm building. 

“Um… Undyne?”

Alphys’ voice snapped her out of it. She was looking back at Undyne, blushing. “U-um… enjoying yourself b-back there?”

Undyne looked down at Alphys’ butt, slick with the moisture from her dick, and realized she had almost gotten off before even sticking it in. “Oh. Uh. Sorry.” She rubbed against Alphys’ ass a few more times before finally pulling back and lining up with her asshole. 

“Ready?” Undyne asked, her dick gently gently prodding against Alphys’ anus.

“Nnnn…” Alphys breathed deep, try to relax as each touch of Undyne’s dick sent shivers up her body. “Okay… go slow…”

Undyne pressed her dick firmly against Alphys’ asshole, and with some resistance, slowly slid inside. 

“A-ahhh… “ Alphys’ legs shook as Undyne slowly pushed inside her, spreading her wide open. Her own dick twitched as Undyne’s bumped up against something inside her, forcing another moan from deep in her body.

Finally, the base of Undyne’s dick met Alphys’ ass. Undyne was panting herself, Alphys’ asshole gripping her dick tightly, squeezing her shaft. She leaned forward over Alphys’ back, reaching around and cupping her breasts in her hands. “You good?”

Alphys nodded, still too breathless to form words.

“We can stop if you’re not…” Undyne trailed off as Alphys began slowly pulling out.  _ Should have figured. It was stupid to force her to- _

Alphys stopped, Undyne’s dick halfway out, and then steadily pushed her rear back towards Undyne. She bottomed out on her dick again, eliciting another breathless gasp, her legs shaking.

Finally, Alphys got her wind back. “C-could you, uh, m-move, because I-I c-can’t r-r-really…”

Before she could finish, she ran out of breath and her legs collapsed from under her, dropping her flat onto the bed, panting with exertion and pleasure. Undyne’s dick was still fairly deep inside her.

Moving with predatory slowness, Undyne brought herself closer to Alphys, practically lying on top of her. “You sure?” she asked teasingly. She pushed in a little deeper, forcing a moan from Alphys, and kissed her neck, giving it a few touches with her sharp teeth as she ran her hands over Alphys’ body, down her front, playing with her breasts, over her wide hips, and finally squeezing her rear, pushing her soft cheeks closer together around her dick.

Alphys nodded, whining as Undyne extracted barely an inch of her dick before pushing it back in just as slowly. “Y-yeah… p-p-p-please…”

“Please…what?” Undyne said, enjoying herself a little too much. 

“Undyne… this isn't fairrrrr…” Alphys gasped through waves of pleasure. 

“You need to tell me what you want me to do here, Al.” Undyne leaned close to Alphys again, practically whispering in her ear. “Unless…you just want to leave it up to me, and that's hardly fair.”

Alphys lay silent on the bed for a moment, fuming. “P-p-p-please f-f-f-f…” She took a deep breath. “Please fuck me senseless and wreck my ass and use me however roughly you want.” She buried her face in a pillow. Undyne heard a muffled shriek of embarrassment.

Alphys, face still stuffed in the pillow felt Undyne slowly, slowly slide deeper inside her. She bit the pillowcase as the base of  Undyne’s dick met her rear, shivering in pleasure as her ass was stretched out. 

Then, she felt Undyne resting the rest of her body against Alphys’ back. Alphys felt Undyne’s breasts press against her, and then Undyne was running a hand up Alphys’ arm and interlacing her fingers with Alphys’. 

“Al…” Undyne said in a soft, gentle voice, and Alphys felt her other hand caressing her face, pulling her face from the pillow and turning her back to look at Undyne. Gently, Undyne kissed her, feeling their lips together and intertwining their tongues.

“Unnie…” Alphys reveled in the feeling of having Undyne so, so close to her; their bodies together, their lips locked, her dick splitting her wide and pushing at Alphys’ deepest parts. 

As Undyne broke the kiss and pulled slowly away from Alphys, Alphys caught a brief glimpse of a hungry, sharp, predatory look in Undyne’s eye before she placed a hand on the back of Alphys’ head and shoved her roughly back down into the bed. As Alphys gasped in response to Undyne slowly pulling out until nothing more than the tip of her dick was inside, Undyne leaned forward over Alphys once again.

“You asked for it,” she whispered in Alphys’ ear before roughly slamming her hips forward, burying the full length of her dick inside Alphys. Alphys felt her breath forced from her body as Undyne filled her up inside before just as quickly pulling out and then plunging in again even more roughly and then repeating.

It didn't take long for Alphys to turn into an embarrassing, moaning, sloppy mess beneath Undyne’s rough fucking. She moaned and panted into the pillow, Undyne’s strong arms still pinning her down as she had her way with Alphys. Her mouth was hanging open, and she realized with some sort of far-off mortification that she was drooling.

Undyne lifted herself off Alphys and took a firm hold on her ass, thrusting her hips forward against Alphys’ wide ass with a soft slapping noise. Alphys felt Undyne slam in and out of her, and her dick twitched with each thrust. Suddenly, she felt a sharp sting on her rear as Undyne roughly spanked her ass, giving it a little jiggle and sending a shiver through Alphys’ whole body.

Alphys felt Undyne’s hands run up and down her body as she continued to plunge roughly in and out, running to her chest and squeezing her boobs. Undyne gave Alphys’ nipples a sharp pinch, making her moan more.

As she fondled Alphys’ chest, Undyne’s thrusts began to slow down. As Alphys noticed this, she whined insistently and ground her butt back against Undyne with what little strength she had left.

Undyne leaned forward, whispering in Alphys’ ear. “I think we could get a little more comfortable, don’t you?”

Her hands left Alphys’ chest and wrapped around her waist, and before Alphys realized what she was doing, Undyne sat back and pulled Alphys onto her lap. The sudden change of position sent Undyne’s dick slamming even deeper into Alphys.

Alphys gasped as she dropped down hard on Undyne’s dick. “Nggggh! Undyne…” She tried to form words, squirming and twitching at the new depths Undyne’s dick was reaching.

But Undyne didn’t give her any time to catch her breath. Her muscular arms wrapping around Alphys’ thighs, she kept pounding upward, bouncing Alphys up and down on her dick.

Alphys felt like she was floating. Every thrust of Undyne’s dick struck a sweet spot deep inside her, leaving her a breathless, limp mess in Undyne’s strong arms. Any conversation ceased, replaced with nothing but heavy, lustful moans, breathless panting, and strained grunts. Alphys’ dick flopped up and down as Undyne continued to fuck her senseless. If she wasn’t in the throes of pleasure at Undyne so entirely dominating her, Alphys would have been going red with embarrassment. Instead, she moaned harder, letting Undyne use her as she liked.

Finally, Undyne felt herself getting close. As she felt her orgasm push over the edge, she thrust upward once more, burying her dick deep in Alphys’ ass, and reached around to grasp Alphys’ dick, quickly stroking it. It didn’t take long for Alphys, who was already close, to her own peak.

As Undyne grunted and emptied herself inside Alphys, Alphys moaned and came herself, twitching and shooting thick ropes of cum across the bed. She felt Undyne’s cool ejaculate filling her up inside, and she shivered with pleasure as she felt it pool inside and eventually start leaking out around Undyne’s dick.

Finally, fully spent, Undyne lifted Alphys one last time and extracted her dick with a lewd, wet sucking sound. Almost as soon as it was out, Undyne’s dick dissipated. She flopped backwards on the bed, and Alphys fell on top of her as well, both of them breathing hard. Alphys rolled over and nuzzled against Undyne’s neck, kissing her and tasting the sweat on her skin.

They both lay there for a while, panting, sweaty, and spent, Alphys feeling Undyne’s chest rise and fall underneath her, Undyne feeling Alphys’ warmth and sweat against her.

Finally, Alphys let out a deep sigh, cuddling up close to Undyne. “Th-that…was…” She took another deep breath. “Wow.”

“Yeah…” Undyne kissed her back and held her close. “Wow.”

Alphys giggled, shifted next to Undyne, and winced. “A-and, uh, ow. Not g-gonna be sitting very w-well for a while.”

Undyne hugged her. “Sorry.” Her hand wandered not-so-innocently down to Alphys’ butt. “Would it feel better if I gave it a little kiss?”

“H-Hey! Enough of th-that!” Alphys took Undyne’s hand firmly away from her rear, intertwining their fingers. She snuggled against Undyne’s torso.

They lay there for a while, cooling down, cuddling. “Did it feel good?” Undyne asked. “Um, I wasn’t too rough or anything, was I?”

“No, you’re fine. I-I mean, I’m gonna have some trouble w-walking tomorrow but…” Alphys laughed again and kissed Undyne. “It was nice.”

Undyne kissed her back. “Same here.”

 

“Ow!”

Undyne was sitting on the couch, watching TV, when she suddenly felt a zap on her shoulder. She jumped, looked around, and saw Alphys standing behind the couch. “Geez, Al, watch the static there.”

Alphys grinned. “Uh, actually, it’s not static…”

She held up a hand, took a deep breath, and focused. Her hand started to glow. It started small; little sparks and flashes dancing around her palm, and grew into bolts of electricity bouncing between her fingers. She focused a little more, and a ball of electricity appeared in her hand, buzzing and sparking.

Alphys relaxed, and the electricity in her hand dissipated. “I-I know it’s not much, b-but I can do it basically on command now, and-ggh!”

She didn’t finish, because Undyne had jumped over the couch and picked her up in a bear hug “THAT’S GREAT! HOLY CRAP BABE!” Undyne spun Alphys around with glee. “I can’t believe it! You picked it up so fast! I mean, it took me years to do that sort of thing on command, and you’ve already-” Undyne couldn’t finish, she was grinning too widely and proudly. “Just...wow!”

Alphys, now a little dizzy, smiled. “I-I mean, it’s not as impressive as what you could do, b-but I guess it’s a start.”

“Yeah! Hey, I’m real happy for you, Al.” Undyne hugged her close again. “And hey…” she whispered in Alphys’ ear, “I can think of some stuff you could use that for.”

“U-U-Undyne!”


End file.
